2,2′-Homocoupled Azine N,N’-Dioxides or Azine N-Oxides: CDC- or SNAr-Controlled Chemoselectivity was written by Jha, Abadh Kishor;Jain, Nidhi. And the article was included in European Journal of Organic Chemistry in 2017.Name: 2-(m-Tolyl)pyridine This article mentions the following:
An unprecedented Cu(OAc)2– and LiOtBu-mediated homocoupling of azine N-oxides to yield 2,2′-azine N,N’-dioxides is reported. This is the first instance in which copper was used to catalyze the homodimerization reaction, especially of 2-phenylpyridine N-oxides. In the absence of catalytic copper, the reaction follows an alternative pathway, and instead of dioxides it yields 2,2′-azine N-monoxides. This latter protocol works efficiently with a range of N-heterocyclic oxides of pyridine, 2-phenylpyridine, quinoline and N-aryl-1,2,3-triazole. It is scalable, offers high regioselectivity and gives the products in moderate to high yields. The observed chemoselectivity between the copper-assisted and copper-free protocols is routed through oxidative cross-dehydrogenative coupling (CDC) and nucleophilic aromatic substitution of hydrogen (SNAr) pathways, resp. In the experiment, the researchers used many compounds, for example, 2-(m-Tolyl)pyridine (cas: 4373-61-9Name: 2-(m-Tolyl)pyridine).
2-(m-Tolyl)pyridine (cas: 4373-61-9) belongs to pyridine derivatives. Pyridine has a dipole moment and a weaker resonant stabilization than benzene (resonance energy 117 kJ·mol−1 in pyridine vs. 150 kJ·mol−1 in benzene). Halopyridines are particularly attractive synthetic building blocks in a variety of cross-coupling methods, including the Suzuki-Miyaura cross-coupling reaction.Name: 2-(m-Tolyl)pyridine